Apparatuses which al low to prepare and dispense instantaneously carbonated refrigerated beverages, of the type of the carbonated crushed-ice beverages and the like, have been known nowadays.
Such known apparatuses generally consist of one or more tanks suitable to contain the product to be prepared and dispensed, fed to the same tanks through a suitable valve member in which a mixing of the concentrated product with carbonated water is performed, according to a suitable proportion. In each tank are arranged a cooling device for cooling the product to the desired temperature and a mixing device which determines the continuous circulation of the product inside the tank. The circulation member, constituted for example by a screw member driven in rotation about an axis longitudinal to the tank, is suitable for conveying the cooled product towards a frontal zone, where a dispenser device for dispensing the product is arranged. The dispenser device is provided with an obturator element which can be actuated by an external lever member.
To each containment tank are connected means for feeding carbonic anhydride to maintain the same tank under pressure. To this aim, the tanks are provided with a pressure tightening lid. The carbonic anhydride is fed to the tanks by a cylinder by means of a suitable collector member, provided with relative electric valves for discharging the exceeding pressure; single ducts branch out from the collector member, directed to the various tanks. Therefore the feed and discharge of the carbonic anhydride in each tank is performed through a single duct. In practice, the product is introduced inside each tank with the discharge electric valves opened; successively such electric valves are closed and the tanks are set under pressure through the feeding of the carbonic anhydride.
A problem which is complained by the users when using the cited apparatuses is determined by the fact that the mentioned products tend to produce a high quantity of foam. In particular, when loading the product, a lot of foam is produced inside the tank. It results that a part of the product, in the form of foam, could go up to the collector member, until obstructing the electric valves. In these conditions, the failure of the entire feed and discharge system of the carbonic anhydride can occur.
A further problem which derives therefrom is the risk of a possible overpressure inside the containment tanks.